Method for producing glass, optical glass, glass material for press molding, optical element and methods for producing same

Abstract

A process for producing a glass in the production of a glass molded article formed of an optical glass by melting and clarifying a glass raw material to prepare a molten glass and molding said molten glass, the process comprising preparing a glass raw material that gives an oxide glass comprising, by cationic %, 12 to 65% of B 3+ , 0 to 20% of Si 4+ , 0 to 6% of Ge 4+ , 15 to 50% of total of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Sc 3+ and Lu 3+ , 4 to 54% of total of Ta 5+ , Zr 4+ , Ti 4+ , Nb 5+ , W 6+ and Bi 3+ , 0 to 35% of Zn 2+ , 0 to 9% of total of Li + , Na + and K + , and 0 to 15% of total of Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ , a total content of said cationic components in the oxide glass being 99 to 100%, and said glass raw material comprising carbonate and sulfate.

The invention claimed is: 
     
       1. A process for producing a glass in the production of a glass molded article formed of an optical glass by melting and clarifying a glass raw material to prepare a molten glass and molding said molten glass,
 the process comprising preparing a glass raw material that gives an oxide glass comprising, by cationic %, 
 12 to 65% of B 3+ , 
 0 to 20% of Si 4+ , 
 0 to 6% of Ge 4+ , 
 15 to 50% of total of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Sc 3+  and Lu 3+ , 
 4 to 54% of total of Ta 5+ , Zr 4+ , Ti 4+ , Nb 5+ , W 6+  and Bi 3+ , 
 0 to 35% of Zn 2+ , 
 0 to 9% of total of Li + , Na +  and K + , and 
 0 to 15% of total of Mg 2+ , Ca 2+ , Sr 2+  and Ba 2+ , 
 a total content of said cationic components in the oxide glass being 99 to 100%, and said glass raw material comprising carbonate and sulfate. 
 
     
     
       2. A process for producing a glass in the production of a cullet by melting a glass raw material to prepare a molten glass and rapidly cooling said molten glass,
 the process comprising preparing a glass raw material that gives a glass comprising, by cationic %, 
 12 to 65% of B 3+ , 
 0 to 20% of Si 4+ , 
 0 to 6% of Ge 4+ , 
 15 to 50% of total of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Sc 3+  and Lu 3+ , 
 4 to 54% of total of Ta 5+ , Zr 4+ , Ti 4+ , Nb 5+ , W 6+  and Bi 3+ , 
 0 to 35% of Zn 2+ , 
 0 to 9% of total of Li + , Na +  and K + , and 
 0 to 15% of total of Mg 2+ , Ca 2+ , Sr 2+  and Ba 2+ , 
 a total content of said cationic components in the glass being 99 to 100%, and said glass raw material comprising carbonate and sulfate. 
 
     
     
       3. A process for producing a glass, which comprises preparing a cullet according to the process recited in  claim 2 , melting and clarifying said cullet to prepare a molten glass and molding said molten glass, to produce a glass molded material formed of an optical glass comprising, by cationic %,
 12 to 65% of B 3+ , 
 0 to 20% of Si 4+ , 
 0 to 6% of Ge 4+ , 
 15 to 50% of total of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Sc 3+  and Lu 3+ , 
 4 to 54% of total of Ta 5+ , Zr 4+ , Ti 4+ , Nb 5+ , W 6+  and Bi 3+ , 
 0 to 35% of Zn 2+ , 
 0 to 9% of total of Li + , Na +  and K + , and 
 0 to 15% of total of Mg 2+ , Ca 2+ , Sr 2+  and Ba 2+ , 
 a total content of said cationic components in the optical glass being 99 to 100%. 
 
     
     
       4. The process for producing a glass as recited in  claim 1  or  3 , wherein at least one step of said melting and clarifying is carried out in a vessel made of platinum or a platinum alloy. 
     
     
       5. An optical glass that is an oxide glass comprising, by cationic %,
 12 to 65% of B 3+ , 
 0 to 20% of Si 4+ , 
 0 to 6% of Ge 4+ , 
 15 to 50% of total of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Sc 3+  and Lu 3+ , 
 4 to 54% of total of Ta 5+ , Zr 4+ , Ti 4+ , Nb 5+ , W 6+  and Bi 3+ , 
 0 to 35% of Zn 2+ , 
 0 to 9% of total of Li + , Na +  and K + , and 
 0 to 15% of total of Mg 2+ , Ca 2+ , Sr 2+  and Ba 2+ , 
 a total content of said cationic components in the oxide glass being 99% or more, 
 the oxide glass containing carbon and sulfur. 
 
     
     
       6. A press-molding glass material formed of the optical glass recited in  claim 5 . 
     
     
       7. An optical element formed of the optical glass recited in  claim 5 . 
     
     
       8. A process for producing an optical element, which comprises preparing an optical glass according to the process recited in  claim 1  or  3 , and making an optical element from said optical glass. 
     
     
       9. A cullet formed of an oxide glass comprising, by cationic %,
 12 to 65% of B 3+ , 
 0 to 20% of Si 4+ , 
 0 to 6% of Ge 4+ , 
 15 to 54% of total of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Sc 3+  and Lu 3+ , 
 4 to 40% of total of Ta 5+ , Zr 4+ , Ti 4+ , Nb 5+ , W 6+  and Bi 3+ , 
 0 to 35% of Zn 2+ , 
 0 to 9% of total of Li + , Na +  and K + , and 
 0 to 15% of total of Mg 2+ , Ca 2+ , Sr 2+  and Ba 2+ , 
 a total content of said cationic components in the oxide glass being 99% or more, 
 the oxide glass containing carbon and sulfur.